ppmtopgm(1) ppmtopgm(1)
NAME
ppmtopgm - convert a portable pixmap into a portable
graymap
SYNOPSISppmtopgm [ppmfile]
DESCRIPTION
Reads a portable pixmap as input. Produces a portable
graymap as output. The quantization formula used is .299
r + .587 g + .114 b.
Note that although there is a pgmtoppm program, it is not
necessary for simple conversions from pgm to ppm, because
any ppm program can read pgm (and pbm ) files automagi-
cally. pgmtoppm is for colorizing a pgm file. Also, see
ppmtorgb3 for a different way of converting color to gray.
QUOTE
Cold-hearted orb that rules the night
Removes the colors from our sight
Red is gray, and yellow white
But we decide which is right
And which is a quantization error.
SEEALSO
pgmtoppm(1), ppmtorgb3(1), rgb3toppm(1), ppm(5), pgm(5)
AUTHOR
Copyright (C) 1989 by Jef Poskanzer.
23 December 1988 1